reorganize classes so test data is separate from test cases

src/test/java/org/json/junit/data/MyNumberContainer.java

@@ -0,0 +1,13 @@
+package org.json.junit.data;
+
+/**
+ * Class that holds our MyNumber override as a property.
+ * @author John Aylward
+ */
+public class MyNumberContainer {
+    private MyNumber myNumber = new MyNumber();
+    /**
+     * @return a MyNumber.
+     */
+    public Number getMyNumber() {return this.myNumber;}
+}